Stress tensor on null boundaries

Abstract

Using the Brown-York prescription for the definition of quasilocal gravitational energy-momentum tensor on a boundary and also complete canonical structure on a null boundary which has been found recently [Classical Quantum Gravity 36, 015012 (2019)CQGRDG0264-938110.1088/1361-6382/aaef9e], we propose a similar stress tensor on the null boundary. Then we exploit this stress tensor to compute the quasilocal energy and angular momentum for some well-known gravitational solutions. We have found that in addition to reference spacetime method for regularizing total energy, in the case of null boundary we can add a possible counterterm thereby avoiding embedding difficulties.